Carbon Nanotube Sensor to Detect Single Molecules of Explosives

An MIT research team has developed a sensor that can detect a single nanoparticle of an explosive like TNT. Michael Strano led the team of chemical engineers who applied a coating of protein fragments that exists in bee venom on carbon nanotubes. The proteins respond to explosives, particularly nitro-aromatic compounds such as TNT.

The sensors could be more sensitive than current explosives sensors that are deployed at airports, which analyze charged particles traveling through the air with a spectroscope. The new devices enhance the earlier variant by being able to sense single explosive molecules. Operating at atmospheric pressure and room temperature.

Daniel Heller, a Damon Runyon Fellow at MIT's David H. Koch Institute for Integrative Cancer Research, is the chief author of the research paper that describes the technology. The paper has been released in the Proceedings of the National Academy of Sciences. The technology is currently awaiting patent, and utilizes protein fragments called bombolitins.

Carbon nanotube sensors have been made for a wide range of molecules, which include hydrogen peroxide, nitric oxide and toxic agents like nerve gas sarin. The carbon nanotubes couple with a molecule that binds with a particular target causing the tube to brighten or dim.

The innovative sensor shifts the fluorescent light wavelength, instead of altering its intensity when the explosive nanoparticle attaches itself to the bee-venom proteins that are covering the nanotubes. The team also developed a microscope that can read the signal that is invisible to the human eye. The device is user -friendly because ambient light does not affect it.

Every nanotube-peptide pair responds differently to discreet nitro-aromatic compounds. Multiple nanotubes coated in distinct bombolitins are used to spot a fingerprint for every explosive that could be sensed.

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